Flexible shaft terminal



w. W. ELLloTT.

v FLEXIBLE SHAFT TERMINAL. APPLlcAnoN man JULY 23.1920.

1,433,537. Patented 001;. 31,1922.

A TTU/WEL Patented Det. 3l, `1922.

.STATES 1,3353? PATENT OFFICE.A

WINFRED W. CIEDILIO'IWL,` OF JOHNSON CITY,*'NEW YORK, ASSIGNOR TO HIMSELF AND ARTHUR H. SHEAR, OF BINGHAMTON, NEW YORK, COPARTNERS.

i, FLEXIBLESHAFT TERMINAL.

Application'led July 23, 1920. Serial No. 398,330.

To all whom t may concern:

Be it known that l, WINFRED W. ELLIOTT, a citizen of the United States, residing at Johnson City, county ofBroome, and State of New York, have invented certain new yand useful Improvenientsin Flexible Shaft Ter- Ininals, of which the following is a specificatOn. 1

This invention relatesgenerally to flexible shaft terminals, and especially appertains to means, of attachment of the extremities of such shafts-particularly those used 1n driving buff wheels, grinders and other appliances the use of which is likely `to involve the presence of abrasive dust or llymors. i f

:fDrior terminals for such shafts have embodied a slip tongue ofapproximatelysemicircular crosssection, together with asocket having a recess of like outlinejwith which such tongue engages. In using such termi'- nals it has been found that the entiredriv-` ing torque is concentrated at a single point, i. e., one ofthe edges of the fiat side,` thus causing excessive wear of such edge which, when localized, resultsin the tongue .catching in the socket through which it should freely slide; and, in any event, such wear soon results in objectionable looseness of the tongue in its socketwhich can be remedied only by the replacement of one or `both of the parts. w l

It is well recognized', that if such a tongue catches in its socket when'the shaft is subjected to bending during the runningthereof, such shaft will be excessively strained if not permanently injured to a serious extent; and `that excessive looseness of `such a tongue in its socket will result in objectionable chattering and jumping of the shaft during the use thereof. j f

lhen such terminals have been employed in the presenceof abrasive dust or iiyings,

as'- when used `for the operationof grinders` and buff wheels-rapid deterioration of wearing surfaces has resulted from the yad-` mission thereto` of such dust and flyings.`

The manufacture ofy suchv terminals has.

heretofore been diificult and expensive, both because of the difficulty` of producing a socket having a recess of half -round'cross section by-mean of the facilities ordinarily available for such work, andbecause ofthe complex character of the means whichV have heretofore been employed for the purpose of preventing the entrance of dust into the bearing surfaces. i j

j An object of this invention is to provide a form of slip tongue `for such shaft terminals whichywillM greatly decrease wear and consequent likelihood `of catching in the socket, andwhich will substantially decrease the amount oflooseness-and consequent opportunity `for chattering `and backlashwhich would result from a given amount 0f wear `of the parts.

Another object isto provide simple and effective means for excluding dust and flyings from the bearings of such terminals.

Another object is to provide terminals, of the .type indicated, .which can bek econo1nically j manufactured and assembled, which require repairs and replacements of minimum cost and frequency, and which can readily be taken apart for purposes of insperrt-ion, cleaning, lubrication and repairs.

Other purposes willv in part be obvious and will in part be hereinafter more fully pointed out. j

The improvedslip tongue structure of this invention comprises a'tongue` and a socket, said tongue and the recess of said socket having two or more driving faces-such as would be afforded by a. triangular, rectangular or hexagonal cross section-such driving faces being disposed `in substantial symmetry withthe center yof rotation thereof, and the corners `of such tongue being rounded so as to conform to arcs described from said center of rotation. i i

For the purposes of transmitting the driving torquetherebetween and of affording needed strength, asuitable portion of the length of the walls of the end of the recess in the socket into which the tongue is introduced is flattened to conform with the drivingfaces of said tongue, and the rremaining length of said recess is circular in cross section and conforms to ,the rounded corners of said tongue, so as to afford-suitable support thereto and to thereby assist in maintaining said tongue `in suitable alignment with the flattenedwalls of said socket. inasmuch as the cost of producing the Hat-tened portion of the recess increasesin direct proportion to the length thereof, and `is much greater than the cost` of producing the portion of said recess having circular cross section, thel improved `construction describedeffects a distinct economy in the cost of manufacture.

The casing 'ofthe terminal is made ofy 'between suehfcesng. and` the rreisctng @11d f the drvinsmember is @relied by. @slip-f. shaped cap which is securely attached to said member, and the Walls4 of which cap. overlap the end of said casing.

y A groove is formed in the-portion of said casing which is overlapped by the Walls of `saidcap,.an`d a ring of suitable resilient packing material-*such as felt-is placed in said groove. 'Such ringservesto exclude dust and flyings from the bearing surfaces, While not ap'p'reciablyv 'increasing the friction betweenfth'e moving and relatively stationary members of the terminal.v

"Thecap 'isisecured tothe driving member by a suitable threaded connection, and lis supported against a "shoulder ofsaid'member so as to prevent setting' thereof too tightly against "the end ofthe casing'.

' The packing ring is inexpensive and may be 'readily replaced, and becauseof the simple `form and arrangement of the partsthe entire terminal "may A'be inexpensively manufactured and, vassembled and'-'may vbe readily taken apart and put 'together Vagain for purposes of inspection, cleaning, lubrication and repairs. I

In order toenable this invention 'to be more readily understood',4 anv embodiment thereof is shown lin the annexed Adrz'twing and hereinafter described, but this'invention is'not limitedl tothe particular arrangement shoivn 'andf'hereinafter described, yas parts may be'added orl omitted or the form thereof may be altered 'Without departing from the spirit ofv this invention.

f InA the accompanying draiving- Figure lv is "anelevation `of a terminal embodying this invention,""the` part above thefhorizlo'ntal -f'cen'ter line being shown in section; f

Fig. 2 is a section on'the line 2-'2 of Fig.`l;and

'Figj isa perspective view of-the tongue 21and its enlarged end or head22.

Like vreference vcharacters V'denote similar parts throughout;

yThe tongue 21 4shown in Figs. l and has thehead22'formed at one end thereof; said tongue having the fla-t faces 23 so disposed as to provide a rectangular cross section, s'aidrfaces being connected by the rounded corners2/l. The headY 22 has formed ltherein aV suitable tapered recess 25`into which an end lof the fleiible corev26is"fi`rmly secured. f 'The rsocket V27 vhas an opening therethrough,``one end of said openingfbei-ng so formed as to provide a" recess ffo'r receiving the tongue 2l andthe other endl of said opening'be'ing 'threaded for a purposevvhich will be hereinafter -mo1`e""fully`y set forth.I

mest. clearly-indicated by Fig- 2; and Seid v"llie portion -of the 'openingvthrough the socket 27 -ivhic'h extends 'from the rend 28 to the shoulder 29 thereof has a cross section corresponding to that ofthe tongue 2l, 3S

portion of such opening is of such length as toxprovideadeguate strength for the transmission of the desired Vtorque between said tongue fand-'said socket.

The portionof said socket opening Which extends from the shoulder -,29 to thethreadvedl vportion SO'thereof is circular in cross-section, asindicated by the dotted line-of-Fig- 2; vandsaid portion of such ropening is of 'such length that, When'taken With the 'portion of said opening which extends between the end 28"and ftheshoulder 29, a recess is' provided between said end 28 and the threaded portion 30, whichfrecess is of sufficient depth yto receive the tongue 21."

` The circular portion "of suchrecess is concentric and `-in alignment with the rectangular portionthereof, and vthe radius of such circularportion is substantially identical with Ithe radii of the rounded corners of said tongue, so that said recess vwill snugly veng'fagesaid tongue While freely permitting `said' tongue to slide lengthwise therethrough. I' ,t I

` nthe'inanufacture of the socket 27', a hole is bored therethrough, -which" hole is slightly "smaller than the perpendicular distance between *oppositev faces of the tongue 2l.` 'Said hole lis then counterbored from the`end 'loffsa'idsocket `to'jthe shoulder 29,so as to provide a diameter which is but slightlygreater than the diagonal of they tongue 21; and a threadis then cut in the, portion y50 of said"counterbored hole. 'l-he portion of the 'hole which extends be- 105 tween "the end 28 and' the'fshoulder" 29 -is then cut out so as to form a rectangular cross' section With' filleted 'corners snugly conforming With'the cross section of the tongueQ/l.V A

The stud 32' comprises a threaded body and` a vthreaded head, said head being` tightly screwed linto thethreaded portion 3() ofi the socket 27, so that the` under side of `the head ofsaid stud will be substantially flush 115 With4 the end 31 of said socket.

The "sleeve j33 "forms ay bearing for the socket 127, said sleeve being slightly shorter than the Adistance between-'the shoulder 34 of said socket and the end 31 thereof. The l' ends of thesleev'ef are of yreduced fdianr eterso that-an endofthe fer-rulei andthe side yWall of the cup-shaped crap 36 may overlap saidrespectiveends; the `end ovenlappedbysaidferrule being Ithreaded for 125 vattachment thereto, and the end Aoverlapped by the Wallof-said cap having a groove' formed therein for receiving" apaciking ring 38. f

Thecap 36 has an opening therethrough 130 which is threaded to fit the body of the stud 32; and one end of said cap has formed therein a cup-shaped recess of such diameter that the wall thereof will cover and provide a running fit for the reduced-diameter end of the sleeve The outside diameter of said cap is substantially the same as that of the intermediate portion `ofthe sleeve 33, and said cap is arranged to form a substantially continuous and smooth surface therei rial of both the tongue 2l and the socket 27,

with.

rlhe lock nut 39 is fitted to the threaded body of the stud 32, and serves tol hold they cap 36 in intended position thereon.

The ferrule 35 is of substantially the same f outside diameter as the intermediate porj tion of the sleeve 33, and the opening in one end of said ferrule is threaded for `engagement by the threaded end of said sleeve. The opening in the other end of said ferrlile.

is tapered and has threadsformed therein for suitably7 engaging an end of the flexible case 40. The length of saidferrule is such that, when the sleeve 33 is secured thereto, the tongue 2l may be withdrawn from said sleeve until the end thereof is flush with the shoulder 29 of said sleeve without causing any part of the head 22 to project from said sleeve.

In assembling the terminal shown, upon the end of a flexible shaft; the end of the core 26 of such a shaft, to which the tongue 21 is to be attached, is fitted to thetapered recess 25 providedin the head 22, andis securely attached thereto, as by soldering. The end of the flexible case iOis correspondingly fittedinto and 'is secured in position within the tapered opening` provided there" for in an end of the ferrule 35.

The stud 32 having been securely set into the threaded end of the socket 27, said socket is inserted into the threaded end of thev sleeve 33; the packing ring is then placed in the groove 37 which is provided in the opposite end of said sleeve 33; and thecap 36 is then placed upon the stud 32 in such position that the wall of saidcap will pro ject toward said casing, 'and said cap is tightly set against the end 3l of said socket,

thus carrying the wall of said cap over the` ring 33. The nut 39 is then placed upon the stud 32 and securely set against the outer face of said cap 36, for which it serves as a lock nut.

rto

between the core 26 and the stud 32 `'the engagement of the flat drivin@v faces of the tongue 2l with the flat walls oi' the rectangu lar portion vof the socket 27; and relative changes in length between the core 26 and the case 40,v such as those incident to the i bending oftheflexible shaft, are compen-` sated for by the slipping of said tonguein` and out of said socket. j l

The symmetrical disposition of the matedecreases' wear of bearing surfaces.` The C symmetrical disposition of the four pairs o;-

co-engaging drivingl faces of said tongue and socket, with relation to the center of rotation tliereof,-assures a substantially equal 'distribution of the stress of the driving torque between such `pairs of faces, and facilitates relative lengthwise movement therebetween when operating under `loadythus decreasing the wear of such parts incident to use n and also decreasing the strain to which the shaft as a whole will be `subjected when so flexed,k while operating under load, as to tend to Acauserelative changes in length between the core 26 and the case 40.

I claim and desire to secure by Letters Patent of the United States of America:

The combination with a revoluble flexible shaft and a relatively nonrevoluble flexible case therefor: of a terminal comprising a tongue secured to an end of said shaft, said tongue having a cross section comprising a plurality of fragmentary arcs of like radii. and chords joining theendsof said arcs; a socket having a recess into which said tongue projects, such recess being so formedl as to freely permit lengthwise movementof` said-tongue therein, part of the length of such `recess having a cross section corresponding with that of said tongue, and the remaining part olf ythe length of such vrecess having a circular cross section which provides a running fitfor the arcs of said tongue a casing, one end of which is secured to an end of said flexible case and the'other end of which has a groove formed therein, said tongue and said socket being` contained in said casing; a stud carried by said'socket and projecting from said casing; a cap-se cured to said stud and,` overlapping the grooved end ofl said casing; and a packing ringin said groove. e

In witness whereof, I hereunto subscribev my name, this 9th day of July 1920.

wiNrRnn w. ELLIOTT;` 

